2 NaClO3 (aq) → 2 NaCl (aq) + 3 O2 (g)
This is an oxidation-reduction (redox) reaction:
2 ClV + 12 e- → 2 Cl-I (reduction)
6 O-II - 12 e- → 6 O0 (oxidation)
NaClO3 is an oxidizing agent, NaClO3 is a reducing agent.
This is a gas evolution reaction, O2 is the formed gas.